Diabetes Monitoring in Pregnant Women with Type 1 Diabetes: Capillary Blood Glucose or Interstitial Fluid Glucose? A Case Control Study

Background: Type 1 diabetes mellitus is associated with adverse maternal and neonatal outcomes. We aimed to evaluate the impact of CGM use on glycemic control and neonatal and maternal outcomes. Methods: This was a single-center study with prospective longitudinal data collection of pregnant women with T1DM allocated to 1 of 2 monitoring methods: Capillary blood monitoring and interstitial fluid glucose monitoring. Results: A total of 30 patients were enrolled. The average age was 31.26 ± 3.39 years, with an average gestational age of 9.4 ± 3.63 weeks at the first consultation. The average diabetes duration was 15.6 ± 7.36 years, with a mean preconception HbA1c of 8.67 ± 0.95%. The average BMI was 25 ± 2.88 kg/m2, and the average weight gain throughout pregnancy was 8.26 ± 5.84 kg. There was a substantial decrease in TBR compared to the control group. The control group had a slightly greater rate of pregnancy-induced hypertension, toxemia, eclampsia, and premature labor (33%, 13%, 7%, and 40%, respectively) than the CGM group (26%, 7%, 0%, and 26%). The differences were not statistically significant. Furthermore, the control group had a greater rate of preterm birth, neonatal hypoglycemia, NICU admission, and congenital abnormalities (27%, 40%, 46%, and 6.7%, respectively) than the CGM group (20%, 33%, 33%, and 0%, respectively), with no significant differences. The rates of macrosomia (20%), LGA (13%), neonatal respiratory distress (33%), and stillbirth (7%) were comparable between the groups. However, hydramnios occurred slightly more frequently in the CGM group (46% vs 40% in the control group). Conclusion: Early implementation and sustained use of CGM in pregnant women with T1DM may optimize glucose control and mitigate maternal-fetal risks.